Multiple sclerosis is a chronic, autoimmune and inflammatory disease of the Central Nervous System characterized by neuronal demyelination and axonal degeneration. Upper extremity problems are present in MS patients from an early stage, affecting the performance of the individual and leading to a decrease in activity of daily living ability in proportion to the extent of the problem. Action Observation Training is currently being examined as one of the methods used for the improvement of motor disorders and has been shown in the literature to be effective on different functions in neurological diseases.

The aim of this study was to investigate the effects of action observation training with 3D virtual reality on upper extremity functions, fatigue, cognitive functions, activities of daily living and quality of life in MS patients.

Hypothesis 1: Action observation training with 3D virtual reality has an effect on upper extremity functions in MS patients.

Hypothesis 2: Action observation training with 3D virtual reality has an effect on cognitive function in MS patients.

Hypothesis 3: Action observation training with 3D virtual reality has an effect on fatigue in MS patients.

Hypothesis 4: Action observation training with 3D virtual reality has an effect on activities of daily living in MS patients.

Hypothesis 5: Action observation training with 3D virtual reality has an effect on quality of life in MS patients.

The training will involve watching 3D videos of upper limb functions in VR and then repeating the functions by the participants. The AOT group will watch video sequences involving upper limb functions, while the control group will watch landscape videos that are not likely to elicit activity in motor or ANS areas.

In our study, 3D videos of upper limb functions will be recorded with a 360° camera and will be shown to individuals through the VR system from the primary person's perspective.

Inclusion Criteria:

• < 2 years MS diagnosis according to McDonald criteria
• between 3.5 and 6 the EDSS
• Nine Hole Peg Test > 30s for at least one upper extremity
• no change in medication in the last 6 months
• having MS disease with ongoing attacks
• >2 Modified Ashworth Scale in the upper extremities
• MOCA>25

Exclusion Criteria:

• diagnosed with neurological (except MS), cardiopulmonary, metabolic or musculoskeletal disease that would prevent treatment and evaluation
• receiving botulinum toxin treatment in the last 6 months
• visual impairment uncorrected by optical devices
• inability to adapt to treatment based on 3D immersive virtual reality (e.g. with cognitive impairment, communication problems, psychological problems or vestibular system problems)